Oldalképek
PDF
ePub

Another of our salt water plants which we also call tang, (tong) although it belongs to an entirely different species, is the bendel tang (string sear weed), zostera marina. This plant extracts manganese from sea water in which it occurs in only such minute quantities that the finest analysis alone is able to detect it, but the zostera marina contains it in such quanti ties that when its ashes are subjected to the action of hydrochloric acid, chlorine is developed freely, just as it is developed when brown stone, the most important manganese ore, is exposed to the action of the same acid. This manganese must exist in the plants in a soluble combination, because when the plant has been exposed to the influence of the sun, wind, and rain, upon our sand beaches, only a minute portion of the manganese is found remaining, and to find it in a large quantity, fresh and perfectly-doveloped plants must be selected toward the fall of the year. Zostera mo rina is a manganese plant. Upon the so-called Galmeiberg-calamide mountain—near Aix-la-Cha

10 that region. It has been called c lamine violet, (viola calaminaria). It contains zinc, and is so characte istic for this ore of zinc, calamine, that it will only grow upon do posits of calamine, and it has been used as a guide in the detection of new deposits of this important zinc ore. When it is planted in gardens it changes its nature and appearance, probably because the soil does not con tain a sufficient quantity of zinc to secure its development. This violet is a zinc plant.

Is it not now probable that in time, and by means of continued exams nations, we shall find copper, lead, tin, cobalt, nickel, and barytes, plants, nay, that every metal which has not yet been found in the vegetable world, has nevertheless its particular plant, of which it is characteristic. A French chemist in the last century affirmed that he had discovered gold in the vine, and this assertion was entirely, neglected, as it was made at a time when chemical analyses were not very exact, and because it did not conform to our then circle of scientific knowledge, but it deserves to be taken up anew, and examined with all the means of assistance which more modern analyses afford.. · So much at least is rendered evident by these examinations, that metals have a part to perform in the vegetable world; that a lack or excess of them in the soil must have a decided influence upon the growth and de velopment of plants. If wheat always contains copper, which seems to be evident, from the analytical examinations made, we are justified in the supposition, until the contrary is proved, that a soil which does not con tain copper is not suited to the culture of wheat, and it is not improbable

that an increased quantity of copper in the soil will have a decided iniu. ence upon this plant's successful growth.

Every one who has cultivated plants has, more or less, felt the danger of the enemies which have beset nearly all our cultivated plants during the last few years, in the form of a multitude of small, low organisms, which produce, or at least evidence diseases in these different plants. We know these diseases as rust or smut in wheat, the potato disease or rota mildew in the grape, or vine disease, olive tree disease, and some years the currant and gooseberry have been attacked by like plagues. The causes of these diseases are probably of very different natures, but most vegetable physiologists agree that the fungus or fungoid organisms which occur as an external sign of disease, can only obtain their power over the plant when it has already become weakly. As it now appears settled that a small quantity of the above mentioned inorganic substances forms a necessary condition for the well-being and development of plants, the question, whether an entire lack, or a too small quantity of these energetic mineral substances in the soil may not induce the sickliness of plants, which sometimes assumes the character of epidemics among the human race, deserves particular attention.

All agree that this sickliness of plants is in a great degree owing to ex. jessive cultivation, that is to say, to the active interference of man to pro. duce a rich yield of the given plant. But in this expression, “excessive cultivation,” there lies a great uncertainty in regard to the changes which grow out of it in the soil and the plants. Over culture—excessive cultivation, may have the effect of making the soil too porous, so that it may become surcharged with organic matters, and be brought into a 'state of unhealthy fermentation, or by means of the atmospheric air develop too large a quantity of carbonic acid, and an excess of this may act injuriously upon plants, by favoring the abstraction from the soil of too large quantities of inorganic matters, or by favoring the accumulation in the soil of other inorganic elements.

I will now propose as a subject for more exact examination, whether one effect of excessive cultivation may not consist in this, that the energetic mineral substances which form the subject of the present communi. cation, have been extracted from the earth in a relatively too large quan. tity, so that the plants cannot obtain a sufficiency of them for a perfect and vigorous vegetation.

It has been demonstrated by my experiments that the rarer metals in the ashes of plants, taken altogether, stand in a different relation to iron from what they do in the soil, there being, relatively, a much larger proportion of the rarer metals taken up by plants than of iron. This is ap

parent first with manganese, while we are unable, in a large proportion of our different kinds of soil, to demonstrate, except with great difficulty, the existence of manganese, it can be shown in the ashes of plants with the greatest facility, and while generally very peculiar means are required to demonstrate the other metals except iron, in the soil, the existence of copper, lead, tin, &c., in the ashes of plants, can be evidenced by very simple chemical operations. Here, then, a concentration, a collection of these rarer matters has accrued, caused, doubtless by the solubility of their ores in water charged with carbonic acid. Let us consider, now, the peculiar mode in which manganese occurs in sea-weeds: It is in combinations soluble in water, probably with organic acids. As the manganese becomes in. soluble in water upon burning the plant and it is not at all unreasonable to suppose a similar condition of the other metals, it follows again that they would be exposed, upon the rotting of the plants, to be washed away, and the soil would thus lose more rapidly these, according to all probability, highly necessary constituents of a luxuriant vegetation. A consequence of these relations is that the soil must lose these materials by means of active cultivation, and our manures are not able to replace them in a sufficiently large quantity.

It lies in the nature of the matter that the propositions here laid down must be uncertain as yet. The matter is too new, and our observations have been in this regard too limited to cause us to stop, satisfied with our investigations, but we should strive for a far more extended experience before we consider the matter established and decided; and the object of this communication is especially to direct the attention to these substances, which have not hitherto been considered as plant-nourishing. If only a small part of what I have here expressed, as based upon my own and other chemists' experiments, be confirmed by future experiments and observations, an actual progress in our theoretic sciences of the nourishment of plants will have been made, as well as in our practical knowledge of the means of calling forth a strong vegetation.

I will now close this series of remarks with a definite proposition. It is well known that a much-used, and according to my experience, very useful means of preventing smut in wheat, is to soak the seed in a weak solution of blue vitriol, (sulphate of copper). If the remarks I have before made are not without foundation, then the copper serve to supply the young plants with this productive materials for nourishment, and thereby protects it from the attacks of those lower organisms. My proposition is that the same experiment be made with the potato; that when planting they shall be carefully soaked or moistened with a very weak solution of blue vitriol. It must not be forgotten that copper is a very poisonous substance, and too much of it would kill the young sprouts. I intend to dry out or wilt some potatoes, and then soak them out in a solution of one part blue vitriol and a thousand parts of water.

Translated from the Swedish of Dr. Forschhammer by Dr. C. E. Boyle of Colambus, Ohio

CHEMICAL PHYSIOLOGICAL CHARACTERISTICS OF

THE VARIOUS FORAGE PLANTS.

The following pages are devoted to an examination of the various forage plants, and, without further preface, we commence with one of the most important, namely, the varieties of clover.

CLOVER. The principal varieties of clover and their organic composition, according to the analysis of the same will be found complete in the following table:

[blocks in formation]
[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]

86

[ocr errors]
[ocr errors]

RED CLOVER newly mown (Trifolium pratense
From Hoenheim before blooming........

87.4 3.3 4.2 3.7

3.7 1.4 Emil Woltr. * " during

83.11 2.8! 6.0 6.7 " " after

80.91 2.21 6.0 9.6 1.3 ockern beginning to bloom.

83.1 3.2 8.1 4.2 u " in full

8.9 1.6 very young.......

6.7| 1.4

Ritthausen. " in full bloom....:

79.5 3.3 8.9 6.7 1.6 Cirencester beginning to bloom

4.3 9.1 3.8) 1.8 in full

80.6 3.6

1.91 Voelker. Moglin beginning to

81.5 3.01

1.3 Eichborn. Elsaz before

82.4

1.6 Boussingaalt " in full

77.0 3.1 12.21 1.4) « Gollmitz in full bloom.......

71.3 3.3 15.9 7.21 2.31 Hellriege Boitzenburg in full bloom

79.9 2.4 10.9 5.9 1.81 a Proskau, first catting...............

76.4 6.21 10.3 5.3.1.6 Halwa. 44 second " ............

80.0 5.9 7.81 4.6 1.7)

79.3 3.7 9.6 6.8 1.6 1:2.6 Average analysis of 14 samples of clover 79.71 3.9 9.11 5.3 1.9 1:2.4 Way.

..

....

2.7

9.11

M

ean ......................

« ElőzőTovább »